D4 vs. D800 high ISO overlays

I felt that a lot of the "downsized" comparisons didn't properly compare D4 high ISO performance vs. D800. Here are some overlays, taken from the RAW studio test shots here on DPREVIEW. They show D4 high ISO images, with overlays of D800 (resized to 16mp).

As you can see, they're not exactly the same. D800 is at least a full stop behind D4, even when downsized.